- Both the table and the graph show the amount of beads consumed per cell under each temperature. Under a cold temperature of 5° C, the Tetrahymena do not take in any beads
- Under a hot temperature of 50 °C the Tetrahymena take in an average of .12 beads
- Under the room temperature setting of 20 °C the Tetrahymena take in an average of 1.15 beads, which is significantly more than the hot and cold settings.
- Both the table and the graph show the amount of beads consumed per cell under each temperature. Under a cold temperature of 5° C, the Tetrahymena do not take in any beads
- Under a hot temperature of 50 °C the Tetrahymena take in an average of .12 beads
- Under room temperature of 20 °C an average of 1.15 beThe Tetrahymena took in significantly more beads when it was under room temperature
The Affects of Temperature on the Eating Patterns of Tetrahymena
Introduction and Background
- In protozoa, phagocytosis is a feeding mechanism.
- Particles are brought into the cell in large endocytic vesicles called phagosomes.
- Phagosomes fuse with lysosomes and digestion of the ingested particles occurs.
- Tetrahymena are ciliated single-celled protozoa
Discussion and Conclusion
- It was found that the Tetrahymena would ingest the greatest amount of the blue polystyrene beads when exposed to a room temperature setting
- Data clearly shows that at room temperature, the Tetrahymena ingest an average of 1.15 beads per cell, whereas in cold and hot temperatures, the Tetrahymena ingest an average of less than 1 bead per cell.
- Duhra, J. K., Fan, L., Gill, V. S., Lee, J. J., & Yeon, J. (2014). The effect of temperature on the population size of Tetrahymena thermophila. The Expedition, 3.
- Narrow the temperature range to determine accurate range that Tetrahymena can live
- Better understand the factors that contribute to phagocytosis and test other variables that could influence the rate that phagocytosis occurs
Hypothesis and Rationale
- If 50 μl of Tetrahymena are placed in hot, cold, and neutral temperatures, more blue polystyrene beads will be consumed in the hot temperatures due to an increase in activity of the protozoa
- By conducting this experiment, one is able to draw conclusions regarding this biological observation seen within Tetrahymena.
- It's through scientific experiments like this that allows one to gain a better understanding of phagocytosis, and whether temperature can influence the rate of consumption.
Methods and Experimental Design
Variables
Design
Independent- temperature of the environment that the Tetrahymena were placed in before they were fed.
Dependent- amount of beads consumed
Variables we controlled: amount of beads we administered to the Tetrahymena
Controls:
Positive Control- room temperature
Negative Control- Tetrahymena that has not been combined with any beads
We administered 50 μL of Tetrahymena into 9 1.7 mL contrifuge tubes using the Gilson Pipetman P-200 (3 for cold temperature, 3 for room temperature, and 3 for hot temperature). Once the 9 contrifuge tubes were ready, we placed three of each tube into the three different temperature water baths for 5 minutes. After the 5 minutes, we administered 20 μL of the polystyrene beads into all 9 of the contrifuge tubes and allow 1 minute for the Tetrahymena to eat the beads. After 1 minute, we used the glutaraldehyde to kill the Tetrahymena. We placed a sample of each of the 9 contrifuge tubes onto glass slides to analyze under the microscope. While under the microscope, we counted the amount of beads each cell consumed within the 25 cells in the middle of the slide to eliminate biases.
Materials
- Gilson Pipetman P-20, P-200, P-1000
- Olympus CH-2 brightfield microscope
- 9 empty 1.7 mL centrifuge tubes
- Glutaraldehyde
- Tetrahymena
- Polystyrene beads
- Ice bucket with temperature between 0°C-5°C
- Water bucket at room temperature 20°C-25°C
- Hot water bucket with temperature between 50°C- 55°C
Katie Belden, Jenny Kushner, Becca Anderson, Joey Solla